Temptation control Overcoming the temptation to eat chocolate, cake and chips is thwarted by the positive thoughts many of us associate with junk food, a study has found.

The findings, published in a recent issue of Psychology and Health, could one day help obese people cut down on their calorie intake, say researchers.

Despite having the motivation to do so, many individuals struggle to successfully minimise their consumption of unhealthy snack foods, says co-author Ashleigh Haynes, a PhD student in applied cognitive psychology at Flinders University.

"Unfortunately, they're the (foods) we tend to find most attractive and enjoyable to eat," she says.

Most people tend to automatically associate unhealthy snack foods with positive feelings and concepts, says Haynes, adding this may have roots in evolution and our life experiences.

There are a growing number of studies that have studied the link between how we feel about food and how much we eat but Haynes was interested in studying a very particular combination of factors.

"The aim of this recent study was to investigate how our automatic evaluation of food (as positive or negative), and the experience of temptation, interact to influence unhealthy snack consumption," says Haynes.

She and colleagues presented 192 people with four unhealthy junk foods and then got them to rate how much they felt tempted by them on a scale of 1 to 7.

The researchers then got the participants to associate the foods with positive and negative words to assess their 'implicit evaluation' of the foods.

Finally, they measured how much of the foods the participants ate in a 10 minute period.

"The more negative implicit evaluation of food, the less tempted people felt and the less of the food they ate," says Haynes.

Re-training the brain

Haynes says there is some evidence that it is possible to re-train the associations the brain makes with junk food.

"Instead of associating unhealthy foods with positive concepts, we can associate them with more negative concepts in an attempt to reduce the strength of temptation experienced and therefore more successfully minimise snack food consumption," she says.

Such programs generally condition people using a series of pictures on a computer screen, she says.

Negative pictures are shown at the same time as unhealthy food pictures, thereby enhancing the brain connections between unhealthy food and negative concepts.

To date, however, these programs have met with variable success at reducing people's consumption of unhealthy snack foods, says Haynes.

She says her most recent findings reveal the limitations of such programs by showing that negative associations can only reduce the strength of temptation.

This suggests the programs need to be supplemented by other strategies that boost our ability to resist temptation, no matter its strength, in the interests of our longer term goals, says Haynes.

"Eating chocolate cake, for example, brings immediate reward in the form of enjoyment and pleasure, but in the long term, we know that giving in to this temptation consistently over time will be bad for our health," she says.

Bigger picture

Professor Peter Lovibond of University of New South Wales school of psychology, who was not involved in the study, says it's important to pursue as many strategies as possible to help reduce overconsumption of junk food.

Such strategies will also be useful in dealing with other problems involving drugs, alcohol and gambling, says Lovibond, who is an expert in human associative learning.

But, he says, it's important to consider the positive associations made with energy-dense foods in the broader society. For example such associations occur in advertising and at gatherings such as children's parties.

"You are battling uphill when you try to reverse those associations," says Lovibond.

He says broader public health strategies such as junk food taxes will be important in overall efforts to reduce consumption of unhealthy snacks.